1. Field of the Invention
The present invention relates to a serial fan module and a frame structure thereof, and more particularly to a serial fan module and frame structure thereof capable of increasing static pressure of the airflow at the outlet, reducing noise and improving unstable flow field.
2. Description of the Related Art
As efficacy of electronic devices continue to increase, heat dissipating devices and heat dissipating systems are playing more critical roles within the electronic devices. Poor heat dissipation can lead to equipment damage or failure.
In particular, heat dissipating devices are playing a greater role for microelectronic elements and devices (e.g. integrated circuit, IC). Due to increased integration and advancement of packaging technology, integrated circuit area is increasingly being reduced and heat per unit area is thus increasingly being increased. Thus, high efficacy heat dissipating devices have continuously been under active development by those in the field.
Heat per unit area of electronic products is increasingly being increased and can not be effectively dissipated by using a single fan. Thus, several fans are combined to solve the problem of poor heat-dissipating capability of a single fan. Referring to FIG. 1, a cross section of conventional combined two fans is shown, wherein the ribs 12 of the inlet fan 11a only function as connecting the frame body 111 and the motor base 17 rather than guiding airflow. Thus, the airflow from the inlet fan 11a becomes turbulent when arriving at the outlet fan 11b, so that the flow field is unstable. As a result, the outlet fan 11b fails to perform normally, the air pressure at the outlet fan 11b is reduced, and the combined fans 1 do not perform as expected. Furthermore, due to the unstable flow field, the airflow exiting from the outlet fan 11b is not entirely directed to the target heat source. Thus, the combined fans 1 are inefficient. Furthermore, the combined two fans 1 tend to produce noise and vibrations during operation.